libs/backends/portaudio/portaudio_io.cc

   1 /*
   2  * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
   3  * Copyright (C) 2015 Tim Mayberry <mojofunk@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <assert.h>
  24 #include <glibmm.h>
  25 #include "portaudio_io.h"
  26
  27 #ifdef WITH_ASIO
  28 #include "pa_asio.h"
  29 #endif
  30
  31 #include "pbd/compose.h"
  32
  33 #include "debug.h"
  34
  35 #define INTERLEAVED_INPUT
  36 #define INTERLEAVED_OUTPUT
  37
  38 using namespace ARDOUR;
  39
  40 PortAudioIO::PortAudioIO ()
  41         : _state (-1)
  42         , _initialized (false)
  43         , _capture_channels (0)
  44         , _playback_channels (0)
  45         , _stream (0)
  46         , _input_buffer (0)
  47         , _output_buffer (0)
  48         , _cur_sample_rate (0)
  49         , _cur_input_latency (0)
  50         , _cur_output_latency (0)
  51         , _host_api_index(-1)
  52 {
  53 }
  54
  55 PortAudioIO::~PortAudioIO ()
  56 {
  57         if (_state == 0) {
  58                 pcm_stop();
  59         }
  60         if (_initialized) {
  61                 Pa_Terminate();
  62         }
  63
  64         clear_device_lists ();
  65
  66         free (_input_buffer); _input_buffer = NULL;
  67         free (_output_buffer); _output_buffer = NULL;
  68 }
  69
  70 std::string
  71 PortAudioIO::control_app_name (int device_id) const
  72 {
  73         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
  74         std::string app_name;
  75
  76         if (info == NULL) {
  77                 DEBUG_AUDIO (string_compose ("Unable to determine Host API from index %1\n",
  78                                              _host_api_index));
  79                 return app_name;
  80         }
  81
  82         PaHostApiTypeId type_id = info->type;
  83
  84 #ifdef WITH_ASIO
  85         if (type_id == paASIO) {
  86                 // is this used for anything, or just acts as a boolean?
  87                 return "PortaudioASIO";
  88         }
  89 #endif
  90
  91         return app_name;
  92 }
  93
  94 void
  95 PortAudioIO::launch_control_app (int device_id)
  96 {
  97 #ifdef WITH_ASIO
  98         PaError err = PaAsio_ShowControlPanel (device_id, NULL);
  99
 100         if (err != paNoError) {
 101                 // error << ?
 102                 DEBUG_AUDIO (string_compose (
 103                     "Unable to show control panel for device with index %1\n", device_id));
 104         }
 105 #endif
 106 }
 107
 108 int
 109 PortAudioIO::available_sample_rates(int device_id, std::vector<float>& sampleRates)
 110 {
 111         static const float ardourRates[] = { 8000.0, 22050.0, 24000.0, 44100.0, 48000.0, 88200.0, 96000.0, 176400.0, 192000.0};
 112
 113         if (!initialize_pa()) return -1;
 114
 115         // TODO use  separate int device_input, int device_output ?!
 116         if (device_id == -1) {
 117                 device_id = get_default_input_device ();
 118         }
 119
 120         DEBUG_AUDIO (
 121             string_compose ("Querying Samplerates for device %1\n", device_id));
 122
 123         sampleRates.clear();
 124         const PaDeviceInfo* nfo = Pa_GetDeviceInfo(device_id);
 125
 126         if (nfo) {
 127                 PaStreamParameters inputParam;
 128                 PaStreamParameters outputParam;
 129
 130                 inputParam.device = device_id;
 131                 inputParam.channelCount = nfo->maxInputChannels;
 132                 inputParam.sampleFormat = paFloat32;
 133                 inputParam.suggestedLatency = 0;
 134                 inputParam.hostApiSpecificStreamInfo = 0;
 135
 136                 outputParam.device = device_id;
 137                 outputParam.channelCount = nfo->maxOutputChannels;
 138                 outputParam.sampleFormat = paFloat32;
 139                 outputParam.suggestedLatency = 0;
 140                 outputParam.hostApiSpecificStreamInfo = 0;
 141
 142                 for (uint32_t i = 0; i < sizeof(ardourRates)/sizeof(float); ++i) {
 143                         if (paFormatIsSupported == Pa_IsFormatSupported(
 144                                                 nfo->maxInputChannels > 0 ? &inputParam : NULL,
 145                                                 nfo->maxOutputChannels > 0 ? &outputParam : NULL,
 146                                                 ardourRates[i])) {
 147                                 sampleRates.push_back (ardourRates[i]);
 148                         }
 149                 }
 150         }
 151
 152         if (sampleRates.empty()) {
 153                 // fill in something..
 154                 sampleRates.push_back (44100.0);
 155                 sampleRates.push_back (48000.0);
 156         }
 157
 158         return 0;
 159 }
 160
 161 #ifdef WITH_ASIO
 162 bool
 163 PortAudioIO::get_asio_buffer_properties (int device_id,
 164                                          long& min_size_frames,
 165                                          long& max_size_frames,
 166                                          long& preferred_size_frames,
 167                                          long& granularity)
 168 {
 169         // we shouldn't really need all these checks but it shouldn't hurt
 170         const PaDeviceInfo* device_info = Pa_GetDeviceInfo(device_id);
 171
 172         if (!device_info) {
 173                 DEBUG_AUDIO (string_compose (
 174                     "Unable to get device info from device index %1\n", device_id));
 175                 return false;
 176         }
 177
 178         const PaHostApiInfo* info = Pa_GetHostApiInfo (device_info->hostApi);
 179
 180         if (info == NULL) {
 181                 DEBUG_AUDIO (string_compose (
 182                     "Unable to determine Host API from device index %1\n", device_id));
 183                 return false;
 184         }
 185
 186         if (info->type != paASIO) {
 187                 DEBUG_AUDIO (string_compose (
 188                     "ERROR device_id %1 is not an ASIO device\n", device_id));
 189                 return false;
 190         }
 191
 192         PaError err = PaAsio_GetAvailableBufferSizes (device_id,
 193                                                       &min_size_frames,
 194                                                       &max_size_frames,
 195                                                       &preferred_size_frames,
 196                                                       &granularity);
 197
 198         if (err != paNoError) {
 199                 DEBUG_AUDIO (string_compose (
 200                     "Unable to determine available buffer sizes for device %1\n", device_id));
 201                 return false;
 202         }
 203         return true;
 204 }
 205
 206 bool
 207 PortAudioIO::get_asio_buffer_sizes (int device_id, std::vector<uint32_t>& buffer_sizes)
 208 {
 209         long min_size_frames = 0;
 210         long max_size_frames = 0;
 211         long preferred_size_frames = 0;
 212         long granularity = 0;
 213
 214         if (!get_asio_buffer_properties (device_id,
 215                                          min_size_frames,
 216                                          max_size_frames,
 217                                          preferred_size_frames,
 218                                          granularity)) {
 219                 DEBUG_AUDIO (string_compose (
 220                     "Unable to get device buffer properties from device index %1\n", device_id));
 221                 return false;
 222         }
 223
 224         DEBUG_AUDIO (string_compose ("ASIO buffer properties for device %1, "
 225                                      "min_size_frames: %2, max_size_frames: %3, "
 226                                      "preferred_size_frames: %4, granularity: %5\n",
 227                                      device_id,
 228                                      min_size_frames,
 229                                      max_size_frames,
 230                                      preferred_size_frames,
 231                                      granularity));
 232
 233 #ifdef USE_ASIO_MIN_MAX_BUFFER_SIZES
 234         if (min_size_frames >= max_size_frames) {
 235                 buffer_sizes.push_back (preferred_size_frames);
 236                 return true;
 237         }
 238
 239         long buffer_size = min_size_frames;
 240         while (buffer_size <= max_size_frames) {
 241                 buffer_sizes.push_back (buffer_size);
 242
 243                 if (granularity <= 0) {
 244                         // buffer sizes are power of 2
 245                         buffer_size = buffer_size * 2;
 246                 } else {
 247                         buffer_size += granularity;
 248                 }
 249         }
 250 #else
 251         buffer_sizes.push_back (preferred_size_frames);
 252 #endif
 253         return true;
 254 }
 255 #endif
 256
 257 bool
 258 PortAudioIO::get_default_buffer_sizes (int device_id, std::vector<uint32_t>& buffer_sizes)
 259 {
 260         static const uint32_t ardourSizes[] = { 64, 128, 256, 512, 1024, 2048, 4096 };
 261         for(uint32_t i = 0; i < sizeof(ardourSizes)/sizeof(uint32_t); ++i) {
 262                 buffer_sizes.push_back (ardourSizes[i]);
 263         }
 264         return true;
 265 }
 266
 267 int
 268 PortAudioIO::available_buffer_sizes(int device_id, std::vector<uint32_t>& buffer_sizes)
 269 {
 270 #ifdef WITH_ASIO
 271         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 272
 273         if (info == NULL) {
 274                 DEBUG_AUDIO (string_compose ("Unable to determine Host API from index %1\n",
 275                                              _host_api_index));
 276                 return -1;
 277         }
 278
 279         PaHostApiTypeId type_id = info->type;
 280
 281         if (type_id == paASIO) {
 282                 if (get_asio_buffer_sizes (device_id, buffer_sizes)) {
 283                         return 0;
 284                 }
 285         }
 286 #endif
 287
 288         get_default_buffer_sizes (device_id, buffer_sizes);
 289
 290         return 0;
 291 }
 292
 293 void
 294 PortAudioIO::input_device_list(std::map<int, std::string> &devices) const
 295 {
 296         for (std::map<int, paDevice*>::const_iterator i = _input_devices.begin ();
 297              i != _input_devices.end ();
 298              ++i) {
 299                 devices.insert (std::pair<int, std::string>(i->first, Glib::locale_to_utf8(i->second->name)));
 300         }
 301 }
 302
 303 void
 304 PortAudioIO::output_device_list(std::map<int, std::string> &devices) const
 305 {
 306         for (std::map<int, paDevice*>::const_iterator i = _output_devices.begin ();
 307              i != _output_devices.end ();
 308              ++i) {
 309                 devices.insert (std::pair<int, std::string>(i->first, Glib::locale_to_utf8(i->second->name)));
 310         }
 311 }
 312
 313 bool
 314 PortAudioIO::initialize_pa ()
 315 {
 316         PaError err = paNoError;
 317
 318         if (!_initialized) {
 319                 err = Pa_Initialize();
 320                 if (err != paNoError) {
 321                         return false;
 322                 }
 323                 _initialized = true;
 324         }
 325
 326         return true;
 327 }
 328
 329 void
 330 PortAudioIO::host_api_list (std::vector<std::string>& api_list)
 331 {
 332         if (!initialize_pa()) return;
 333
 334         PaHostApiIndex count = Pa_GetHostApiCount();
 335
 336         if (count < 0) return;
 337
 338         for (int i = 0; i < count; ++i) {
 339                 const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
 340                 if (info->name != NULL) { // possible?
 341                         api_list.push_back (info->name);
 342                 }
 343         }
 344 }
 345
 346 bool
 347 PortAudioIO::set_host_api (const std::string& host_api_name)
 348 {
 349         PaHostApiIndex new_index = get_host_api_index_from_name (host_api_name);
 350
 351         if (new_index < 0) {
 352                 DEBUG_AUDIO ("Portaudio: Error setting host API\n");
 353                 return false;
 354         }
 355         _host_api_index = new_index;
 356         _host_api_name = host_api_name;
 357         return true;
 358 }
 359
 360 PaHostApiIndex
 361 PortAudioIO::get_host_api_index_from_name (const std::string& name)
 362 {
 363         if (!initialize_pa()) return -1;
 364
 365         PaHostApiIndex count = Pa_GetHostApiCount();
 366
 367         if (count < 0) {
 368                 DEBUG_AUDIO ("Host API count < 0\n");
 369                 return -1;
 370         }
 371
 372         for (int i = 0; i < count; ++i) {
 373                 const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
 374                 if (info != NULL && info->name != NULL) { // possible?
 375                         if (name == info->name) {
 376                                 return i;
 377                         }
 378                 }
 379         }
 380         DEBUG_AUDIO (string_compose ("Unable to get host API from name: %1\n", name));
 381
 382         return -1;
 383 }
 384
 385 PaDeviceIndex
 386 PortAudioIO::get_default_input_device ()
 387 {
 388         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 389         if (info == NULL) return -1;
 390         return info->defaultInputDevice;
 391 }
 392
 393 PaDeviceIndex
 394 PortAudioIO::get_default_output_device ()
 395 {
 396         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 397         if (info == NULL) return -1;
 398         return info->defaultOutputDevice;
 399 }
 400
 401 void
 402 PortAudioIO::clear_device_lists ()
 403 {
 404         for (std::map<int, paDevice*>::const_iterator i = _input_devices.begin (); i != _input_devices.end(); ++i) {
 405                 delete i->second;
 406         }
 407         _input_devices.clear();
 408
 409         for (std::map<int, paDevice*>::const_iterator i = _output_devices.begin (); i != _output_devices.end(); ++i) {
 410                 delete i->second;
 411         }
 412         _output_devices.clear();
 413 }
 414
 415 void
 416 PortAudioIO::add_default_devices ()
 417 {
 418         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 419         if (info == NULL) return;
 420
 421         const PaDeviceInfo* nfo_i = Pa_GetDeviceInfo(get_default_input_device());
 422         const PaDeviceInfo* nfo_o = Pa_GetDeviceInfo(get_default_output_device());
 423         if (nfo_i && nfo_o) {
 424                 _input_devices.insert (std::pair<int, paDevice*> (-1,
 425                                         new paDevice("Default",
 426                                                 nfo_i->maxInputChannels,
 427                                                 nfo_o->maxOutputChannels
 428                                                 )));
 429                 _output_devices.insert (std::pair<int, paDevice*> (-1,
 430                                         new paDevice("Default",
 431                                                 nfo_i->maxInputChannels,
 432                                                 nfo_o->maxOutputChannels
 433                                                 )));
 434         }
 435 }
 436
 437 void
 438 PortAudioIO::add_devices ()
 439 {
 440         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 441         if (info == NULL) return;
 442
 443         int n_devices = Pa_GetDeviceCount();
 444
 445         DEBUG_AUDIO (string_compose ("PortAudio found %1 devices\n", n_devices));
 446
 447         for (int i = 0 ; i < n_devices; ++i) {
 448                 const PaDeviceInfo* nfo = Pa_GetDeviceInfo(i);
 449
 450                 if (!nfo) continue;
 451                 if (nfo->hostApi != _host_api_index) continue;
 452
 453                 DEBUG_AUDIO (string_compose (" (%1) '%2' '%3' in: %4 (lat: %5 .. %6) out: %7 "
 454                                              "(lat: %8 .. %9) sr:%10\n",
 455                                              i,
 456                                              info->name,
 457                                              nfo->name,
 458                                              nfo->maxInputChannels,
 459                                              nfo->defaultLowInputLatency * 1e3,
 460                                              nfo->defaultHighInputLatency * 1e3,
 461                                              nfo->maxOutputChannels,
 462                                              nfo->defaultLowOutputLatency * 1e3,
 463                                              nfo->defaultHighOutputLatency * 1e3,
 464                                              nfo->defaultSampleRate));
 465
 466                 if ( nfo->maxInputChannels == 0 && nfo->maxOutputChannels == 0) {
 467                         continue;
 468                 }
 469
 470                 if (nfo->maxInputChannels > 0) {
 471                         _input_devices.insert (std::pair<int, paDevice*> (i, new paDevice(
 472                                                         nfo->name,
 473                                                         nfo->maxInputChannels,
 474                                                         nfo->maxOutputChannels
 475                                                         )));
 476                 }
 477                 if (nfo->maxOutputChannels > 0) {
 478                         _output_devices.insert (std::pair<int, paDevice*> (i, new paDevice(
 479                                                         nfo->name,
 480                                                         nfo->maxInputChannels,
 481                                                         nfo->maxOutputChannels
 482                                                         )));
 483                 }
 484         }
 485 }
 486
 487 void
 488 PortAudioIO::discover()
 489 {
 490         DEBUG_AUDIO ("PortAudio: discover\n");
 491         if (!initialize_pa()) return;
 492
 493         clear_device_lists ();
 494         add_default_devices ();
 495         add_devices ();
 496 }
 497
 498 void
 499 PortAudioIO::pcm_stop ()
 500 {
 501         if (_stream) {
 502                 Pa_CloseStream (_stream);
 503         }
 504         _stream = NULL;
 505
 506         _capture_channels = 0;
 507         _playback_channels = 0;
 508         _cur_sample_rate = 0;
 509         _cur_input_latency = 0;
 510         _cur_output_latency = 0;
 511
 512         free (_input_buffer); _input_buffer = NULL;
 513         free (_output_buffer); _output_buffer = NULL;
 514         _state = -1;
 515 }
 516
 517 int
 518 PortAudioIO::pcm_start()
 519 {
 520         PaError err = Pa_StartStream (_stream);
 521
 522         if (err != paNoError) {
 523                 _state = -1;
 524                 return -1;
 525         }
 526         return 0;
 527 }
 528
 529 #ifdef __APPLE__
 530 static uint32_t lower_power_of_two (uint32_t v) {
 531         v--;
 532         v |= v >> 1;
 533         v |= v >> 2;
 534         v |= v >> 4;
 535         v |= v >> 8;
 536         v |= v >> 16;
 537         v++;
 538         return v >> 1;
 539 }
 540 #endif
 541
 542 int
 543 PortAudioIO::pcm_setup (
 544                 int device_input, int device_output,
 545                 double sample_rate, uint32_t samples_per_period)
 546 {
 547         _state = -2;
 548
 549         PaError err = paNoError;
 550         const PaDeviceInfo *nfo_in;
 551         const PaDeviceInfo *nfo_out;
 552         const PaStreamInfo *nfo_s;
 553
 554         if (!initialize_pa()) {
 555                 DEBUG_AUDIO ("PortAudio Initialization Failed\n");
 556                 goto error;
 557         }
 558
 559         if (device_input == -1) {
 560                 device_input = get_default_input_device ();
 561         }
 562         if (device_output == -1) {
 563                 device_output = get_default_output_device ();
 564         }
 565
 566         _capture_channels = 0;
 567         _playback_channels = 0;
 568         _cur_sample_rate = 0;
 569         _cur_input_latency = 0;
 570         _cur_output_latency = 0;
 571
 572         DEBUG_AUDIO (string_compose (
 573             "PortAudio Device IDs: i:%1 o:%2\n", device_input, device_output));
 574
 575         nfo_in = Pa_GetDeviceInfo(device_input);
 576         nfo_out = Pa_GetDeviceInfo(device_output);
 577
 578         if (!nfo_in && ! nfo_out) {
 579                 DEBUG_AUDIO ("PortAudio Cannot Query Device Info\n");
 580                 goto error;
 581         }
 582
 583         if (nfo_in) {
 584                 _capture_channels = nfo_in->maxInputChannels;
 585         }
 586         if (nfo_out) {
 587                 _playback_channels = nfo_out->maxOutputChannels;
 588         }
 589
 590         if(_capture_channels == 0 && _playback_channels == 0) {
 591                 DEBUG_AUDIO ("PortAudio no input or output channels.\n");
 592                 goto error;
 593         }
 594
 595 #ifdef __APPLE__
 596         // pa_mac_core_blocking.c pa_stable_v19_20140130
 597         // BUG: ringbuffer alloc requires power-of-two chn count.
 598         if ((_capture_channels & (_capture_channels - 1)) != 0) {
 599                 DEBUG_AUDIO (
 600                     "Adjusted capture channels to power of two (portaudio rb bug)\n");
 601                 _capture_channels = lower_power_of_two (_capture_channels);
 602         }
 603
 604         if ((_playback_channels & (_playback_channels - 1)) != 0) {
 605                 DEBUG_AUDIO (
 606                     "Adjusted capture channels to power of two (portaudio rb bug)\n");
 607                 _playback_channels = lower_power_of_two (_playback_channels);
 608         }
 609 #endif
 610
 611         DEBUG_AUDIO (string_compose ("PortAudio Channels: in:%1 out:%2\n",
 612                                      _capture_channels,
 613                                      _playback_channels));
 614
 615         PaStreamParameters inputParam;
 616         PaStreamParameters outputParam;
 617
 618         if (nfo_in) {
 619                 inputParam.device = device_input;
 620                 inputParam.channelCount = _capture_channels;
 621 #ifdef INTERLEAVED_INPUT
 622                 inputParam.sampleFormat = paFloat32;
 623 #else
 624                 inputParam.sampleFormat = paFloat32 | paNonInterleaved;
 625 #endif
 626                 inputParam.suggestedLatency = nfo_in->defaultLowInputLatency;
 627                 inputParam.hostApiSpecificStreamInfo = NULL;
 628         }
 629
 630         if (nfo_out) {
 631                 outputParam.device = device_output;
 632                 outputParam.channelCount = _playback_channels;
 633 #ifdef INTERLEAVED_OUTPUT
 634                 outputParam.sampleFormat = paFloat32;
 635 #else
 636                 outputParam.sampleFormat = paFloat32 | paNonInterleaved;
 637 #endif
 638                 outputParam.suggestedLatency = nfo_out->defaultLowOutputLatency;
 639                 outputParam.hostApiSpecificStreamInfo = NULL;
 640         }
 641
 642         // XXX re-consider using callback API, testing needed.
 643         err = Pa_OpenStream (
 644                         &_stream,
 645                         _capture_channels > 0 ? &inputParam: NULL,
 646                         _playback_channels > 0 ? &outputParam: NULL,
 647                         sample_rate,
 648                         samples_per_period,
 649                         paDitherOff,
 650                         NULL, NULL);
 651
 652         if (err != paNoError) {
 653                 DEBUG_AUDIO ("PortAudio failed to start stream.\n");
 654                 goto error;
 655         }
 656
 657         nfo_s = Pa_GetStreamInfo (_stream);
 658         if (!nfo_s) {
 659                 DEBUG_AUDIO ("PortAudio failed to query stream information.\n");
 660                 pcm_stop();
 661                 goto error;
 662         }
 663
 664         _cur_sample_rate = nfo_s->sampleRate;
 665         _cur_input_latency = nfo_s->inputLatency * _cur_sample_rate;
 666         _cur_output_latency = nfo_s->outputLatency * _cur_sample_rate;
 667
 668         DEBUG_AUDIO (string_compose ("PA Sample Rate %1 SPS\n", _cur_sample_rate));
 669
 670         DEBUG_AUDIO (string_compose ("PA Input Latency %1ms, %2 spl\n",
 671                                      1e3 * nfo_s->inputLatency,
 672                                      _cur_input_latency));
 673
 674         DEBUG_AUDIO (string_compose ("PA Output Latency %1ms, %2 spl\n",
 675                                      1e3 * nfo_s->outputLatency,
 676                                      _cur_output_latency));
 677
 678         _state = 0;
 679
 680         if (_capture_channels > 0) {
 681                 _input_buffer = (float*) malloc (samples_per_period * _capture_channels * sizeof(float));
 682                 if (!_input_buffer) {
 683                         DEBUG_AUDIO ("PortAudio failed to allocate input buffer.\n");
 684                         pcm_stop();
 685                         goto error;
 686                 }
 687         }
 688
 689         if (_playback_channels > 0) {
 690                 _output_buffer = (float*) calloc (samples_per_period * _playback_channels, sizeof(float));
 691                 if (!_output_buffer) {
 692                         DEBUG_AUDIO ("PortAudio failed to allocate output buffer.\n");
 693                         pcm_stop();
 694                         goto error;
 695                 }
 696         }
 697
 698         return 0;
 699
 700 error:
 701         _capture_channels = 0;
 702         _playback_channels = 0;
 703         free (_input_buffer); _input_buffer = NULL;
 704         free (_output_buffer); _output_buffer = NULL;
 705         return -1;
 706 }
 707
 708 int
 709 PortAudioIO::next_cycle (uint32_t n_samples)
 710 {
 711         bool xrun = false;
 712         PaError err;
 713         err = Pa_IsStreamActive (_stream);
 714         if (err != 1) {
 715                 //   0: inactive / aborted
 716                 // < 0: error
 717                 return -1;
 718         }
 719
 720         // TODO, check drift..  process part with larger capacity first.
 721         // Pa_GetStreamReadAvailable(_stream) < Pa_GetStreamWriteAvailable(_stream)
 722
 723         if (_playback_channels > 0) {
 724                 err = Pa_WriteStream (_stream, _output_buffer, n_samples);
 725                 if (err) xrun = true;
 726         }
 727
 728         if (_capture_channels > 0) {
 729                 err = Pa_ReadStream (_stream, _input_buffer, n_samples);
 730                 if (err) {
 731                         memset (_input_buffer, 0, sizeof(float) * n_samples * _capture_channels);
 732                         xrun = true;
 733                 }
 734         }
 735
 736
 737         return xrun ? 1 : 0;
 738 }
 739
 740
 741 #ifdef INTERLEAVED_INPUT
 742
 743 int
 744 PortAudioIO::get_capture_channel (uint32_t chn, float *input, uint32_t n_samples)
 745 {
 746         assert(chn < _capture_channels);
 747         const uint32_t stride = _capture_channels;
 748         float *ptr = _input_buffer + chn;
 749         while (n_samples-- > 0) {
 750                 *input++ = *ptr;
 751                 ptr += stride;
 752         }
 753         return 0;
 754 }
 755
 756 #else
 757
 758 int
 759 PortAudioIO::get_capture_channel (uint32_t chn, float *input, uint32_t n_samples)
 760 {
 761         assert(chn < _capture_channels);
 762         memcpy((void*)input, &(_input_buffer[chn * n_samples]), n_samples * sizeof(float));
 763         return 0;
 764 }
 765
 766 #endif
 767
 768
 769 #ifdef INTERLEAVED_OUTPUT
 770
 771 int
 772 PortAudioIO::set_playback_channel (uint32_t chn, const float *output, uint32_t n_samples)
 773 {
 774         assert(chn < _playback_channels);
 775         const uint32_t stride = _playback_channels;
 776         float *ptr = _output_buffer + chn;
 777         while (n_samples-- > 0) {
 778                 *ptr = *output++;
 779                 ptr += stride;
 780         }
 781         return 0;
 782 }
 783
 784 #else
 785
 786 int
 787 PortAudioIO::set_playback_channel (uint32_t chn, const float *output, uint32_t n_samples)
 788 {
 789         assert(chn < _playback_channels);
 790         memcpy((void*)&(_output_buffer[chn * n_samples]), (void*)output, n_samples * sizeof(float));
 791         return 0;
 792 }
 793
 794 #endif